A new generation of electronic, optical or optoelectronic devices such as organic thin film transistors (OTFTs), organic light-emitting transistors (OLETs), organic light-emitting diodes (OLEDs), or organic photovoltaics (OPVs) are fabricated using organic semiconductors as their active components. To be commercially relevant, these organic semiconductor-based devices should be processable in a cost-effective manner.
Several p- and n-channel organic semiconductors have achieved acceptable device performance. For example, OTFTs based on acenes and oligothiophenes (p-channel) and perylenes (n-channel) exhibit carrier mobilities (μ's)>0.5 cm2/V·s in ambient conditions. Furthermore, a variety of polymeric and molecular semiconductor materials incorporating one or more fused thiophene rings have been synthesized and/or proposed as organic semiconductor building blocks, which includes naphthodithiophene rings reported in Umeda, R., et al., Comptes Rendus Chimie (2009), 12(3-4), 378-384; Coropceanu, V., et al., Chemistry—A European Journal (2006), 12(7), 2073-2080; Takahashi, T., et al., JP 2010180151 A; Takimiya, K., et al., WO 2010058692 A1; Katakura, T., et al., JP 2006216814 A; and Katz, H. E., et al., U.S. Pat. No. 5,936,259 A. Although many of these materials exhibit acceptable carrier mobilities, improved processability is required for commercial feasibility. For example, pentacene exhibits high hole mobility >5 cm2/V·s with its highly crystalline nature, but cannot be processed via printing methodologies due to its insolubility.
Accordingly, the art desires new polymeric or molecular semiconductors, particularly those having well-balanced semiconducting properties and processing properties.